Subcellular localization and N-glycosylation of human ABCC6, expressed in MDCKII cells

Biochem Biophys Res Commun. 2003 Aug 22;308(2):263-9. doi: 10.1016/s0006-291x(03)01349-4.


Mutations in the gene coding for a human ABC transporter protein, ABCC6 (MRP6), are responsible for the development of pseudoxanthoma elasticum. Here, we demonstrate that human ABCC6, when expressed by retroviral transduction in polarized mammalian (MDCKII) cells, is exclusively localized to the basolateral membrane. The human ABCC6 in MDCKII cells was found to be glycosylated, in contrast to the underglycosylated form of the protein, as expressed in Sf9 cells. In order to localize the major glycosylation site(s) in ABCC6, we applied limited proteolysis on the fully glycosylated and underglycosylated forms, followed by immunodetection with region-specific antibodies for ABCC6. Our results indicate that Asn15, which is located in the extracellular N-terminal region of human ABCC6, is the only N-glycosylation site in this protein. The polarized mammalian expression system characterized here provides a useful tool for further examination of routing, glycosylation, and function of the normal and pathological variants of human ABCC6.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Cell Line
  • Cell Polarity
  • Dogs
  • Glycosylation
  • Humans
  • Models, Molecular
  • Multidrug Resistance-Associated Proteins / chemistry*
  • Multidrug Resistance-Associated Proteins / genetics
  • Multidrug Resistance-Associated Proteins / metabolism*
  • Mutation
  • Pseudoxanthoma Elasticum / genetics
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Spodoptera
  • Subcellular Fractions / metabolism
  • Transduction, Genetic
  • Trypsin
  • Tunicamycin / pharmacology


  • ABCC6 protein, human
  • Multidrug Resistance-Associated Proteins
  • Recombinant Proteins
  • Tunicamycin
  • Trypsin